COSC4840 Software Engineering

1
COSC-4840 Software Engineering

• Lab Session 5
• Layout Managers in Java
• Or
• How Do I Get My GUI to Look Right?
• Prepared by Nadya Kuzmina
• Based on Creating a GUI with JFC/Swing Trail in
  The Java Tutorial

2
Layout Managers

• A layout manager determines positions of visual
  components within their container.
• It is specified on the container.

3
BorderLayout 1

• A BorderLayout places components in up to five
  areas top, bottom, left, right, and center.
• All extra space is placed in the center area.

4
BoxLayout 1

• The BoxLayout class puts components in a single
  row or column.
• It respects the components' requested maximum
  sizes and also lets you align components.

5
CardLayout 1

• The CardLayout class lets you implement an area
  that contains different components at different
  times.
• A CardLayout is often controlled by a combo box,
  with the state of the combo box determining which
  panel (group of components) the CardLayout
  displays.

6
FlowLayout 1

• FlowLayout is the default layout manager for
  every JPanel.
• It simply lays out components in a single row,
  starting a new row if its container isn't
  sufficiently wide.

7
GridBagLayout 1

• GridBagLayout is a sophisticated, flexible layout
  manager.
• It aligns components by placing them within a
  grid of cells, allowing some components to span
  more than one cell.
• The rows in the grid can have different heights,
  and grid columns can have different widths.

8
GridLayout 1

• GridLayout simply makes a bunch of components
  equal in size and displays them in the requested
  number of rows and columns.

9
FlowLayout 1

• FlowLayout puts components in a row, sized at
  their preferred size.
• If the horizontal space in the container is too
  small to put all the components in one row,
  FlowLayout uses multiple rows.
• If the container is wider than necessary for a
  row of components, the row is, by default,
  centered horizontally within the container.

10
BorderLayout 1

• A BorderLayout has five areas.
• These areas are specified by the BorderLayout
  constants NORTH, WEST, EAST, SOUTH, and CENTER.
• It is recommended that you specify the
  component's location (for example,
  BorderLayout.SOUTH) as one of the arguments to
  the add method. If you leave it out, the
  component will be added to the center, but your
  code will be much less clear.
• If you find that a component is missing from a
  container controlled by a BorderLayout, make sure
  that you specified the component's location and
  that you didn't put another component in the same
  location.

11
GridBagLayout 1

• GridBagLayout is one of the most flexible and
  complex layout managers the Java platform
  provides.
• A GridBagLayout places components in a grid of
  rows and columns, allowing specified components
  to span multiple rows or columns.
• Not all rows necessarily have the same height.
  Similarly, not all columns necessarily have the
  same width.
• Essentially, GridBagLayout places components in
  rectangles (cells) in a grid, and then uses the
  components' preferred sizes to determine how big
  the cells should be.

12
GridBagLayout Constraints

• GridBagConstraints gridBagConstraints4 new
  GridBagConstraints()
• gridBagConstraints4.insets new Insets(20, 1,
  22, 6)
• gridBagConstraints4.gridx 1
• gridBagConstraints4.gridy 2
• gridBagConstraints4.ipadx 23
• gridBagConstraints4.ipady 6
• gridBagConstraints4.gridwidth 2

13
References.

• 1 The Java Tutorial
• Creating a GUI with JFC/Swing Trail
  (http//java.sun.com/docs/books/tutorial/reallybig
  index.htmluiswing).